EC Number   |
Substrates |
Organism |
Products |
Reversibility |
|---|
  4.2.1.110 | D-glucosone |
i.e. D-arabino-hexos-2-ulose. The enzyme dehydrates D-arabino-hexos-2-ulose, generating a double bond between C-3 and C-4. This unsaturated compound is proposed to be the steady-state intermediate characterized by the spectral peak at 265 nm. This intermediate is chemically unstable and rearranges from its strained 1,5 ring form to a more stable 2,6 pyranose structure. Then the enzyme acts a second time, dehydrating this pyranose structure to form cortalcerone |
Polyporus obtusus |
cortalcerone + H2O |
i.e. 5,6-dihydro-6-hydroxy-5-oxo-2H-pyran-6-carboxaldehyde |
? |
| 4.2.1.110 | D-glucosone |
i.e. D-arabino-hexos-2-ulose. The enzyme dehydrates D-arabino-hexos-2-ulose, generating a double bond between C-3 and C-4. This unsaturated compound is proposed to be the steady-state intermediate characterized by the spectral peak at 265 nm. This intermediate is chemically unstable and rearranges from its strained 1,5 ring form to a more stable 2,6 pyranose structure. Then the enzyme acts a second time, dehydrating this pyranose structure to form cortalcerone |
Polyporus obtusus AU124PD |
cortalcerone + H2O |
i.e. 5,6-dihydro-6-hydroxy-5-oxo-2H-pyran-6-carboxaldehyde |
? |
| 4.2.1.110 | D-xylosone |
i.e. D-threo-pentos-2-ulose |
Polyporus obtusus |
? |
the product absorbs at 260 nm but no conversion into a 230 nm-absorbing product occurs. Because of its strained nature, the intermediate still rearranges, losing UV absorbance, but since it lacks the 6th carbon, it cannot form a 2,6-pyranose ring to generate a second substrate for the enzyme |
? |
| 4.2.1.110 | D-xylosone |
i.e. D-threo-pentos-2-ulose |
Polyporus obtusus AU124PD |
? |
the product absorbs at 260 nm but no conversion into a 230 nm-absorbing product occurs. Because of its strained nature, the intermediate still rearranges, losing UV absorbance, but since it lacks the 6th carbon, it cannot form a 2,6-pyranose ring to generate a second substrate for the enzyme |
? |
| 4.2.1.110 | glucosone |
- |
Phanerodontia chrysosporium |
cortalcerone + H2O |
- |
? |
| 4.2.1.110 | glucosone |
- |
Sarcodontia unicolor |
cortalcerone + H2O |
- |
? |
| 4.2.1.110 | glucosone |
20% of the activity with 1,5-anhydro-D-fructose |
Phanerodontia chrysosporium |
cortalcerone + H2O |
- |
? |
| 4.2.1.110 | glucosone |
2-keto glucose |
Phanerodontia chrysosporium |
cortalcerone + H2O |
- |
? |
| 4.2.1.110 | more |
no activity with fructose |
Polyporus obtusus |
? |
- |
? |
| 4.2.1.110 | more |
the enzyme is bifunctional and is also active with glucosone and xylosone, the former is converted to cortalcerone |
Phanerodontia chrysosporium |
? |
- |
? |
